Expansible metal-plate gas-containing cell for sealing transformers with inert gas



- Filed May 16, 1961 Dec. 4, 1962 SHINJI NAKAZAWA 3,067,

EXPANSIBLE METAL-PLATE GAS-CONTAINING CELL FOR SEALING TRANSFORMERS WITH INERT GAS 3 Sheets-Sheet 1 fi PIP/DRAFT 3 Dec. 4, 1.962 SHINJI NAKAZAWA 3,067,277

EXPANSIBLE, METAL-PLATE GAS-CONTAINING cm. FOR

SEALING TRANSFORMERS WITH INERT GAS Filed May 16 196]. 3 Sheets-Sheet 2 Hg; 5 By 6 I i4 i i i i i: I I L g 17 2 1 i i I 7 i i W a Z ,1 5 i ,I/ i Q I I E74 Fig. 8 4

E Mu/77C Arr) i atent fitice 3,057,277- Patented Dec. 4, 1962 3,067,277 EXPANSIBLE METALPLATE GAS CONTAlNlNG CELL FOR SEALING TRANSFURMERS Wl'IH INERT GAS Shinji Nakazawa, 1057, 7-Cl1ome, Hiratsuka Sliinagawakn, Tokyo, Japan Filed May 16, 1961, Ser. No. 110580 7 Claims. (Cl. 174-12) The present invention relates to a gas-containing cell Whose major parts are made with metal plates and which is particularly adapted for use on the transformer previously invented by this inventor under the title Nitrogen- Gas-Sealed Transformer, Japanese Patent No. 206,051, or any other type of transformer having similar properties.

The invention .of Japanese Patent No. 206,051, Nitrogen-Gas-Sealed Transformer, cited above, consists substantially of a nitrogen-gas-sealed transformer having a bag made of such a soft, resilient, gas-tight, durable and flexible material as vinyl resin, or synthetic rubber or any other similar material, whose interior space communicates with the space filled with nitrogen gas in the transformer, and a housing which limits the expansion of the said gascontaining bag. The object of the cited invention is to permit the insulation oil and sealing gas in the transformer to expand and contract without bringing about variation of sealing-gas pressure.

In an example of application of the cited invention, which is depicted in FIG. 1 of the accompanying drawing, the oil-immersed transformer, designated as 101, may be of any desired construction and is provided with a conservator 102 mounted on its top. The lower inner portion of the conservator 102 constitutes an oil reservoir 107 containing part of the insulation oil of the transformer in the customary manner, and the upper portion is filled with dry nitrogen gas 103 acting as the sealing gas. The gascontaining bag 104, made of an aforementioned flexible material, communicates to that space within the conservator filled up with nitrogen gas 103 through a pipe 105. The joint connection between pipe 105 and gascontaining bag 104 as well as the gas passage between the two is made gas-tight to perfectly isolate the contained nitrogen gas from atmospheric air. A housing 105, made'with ferrous plates, limits the expansion of gas containing bag 104 positioned therein. The part designated as SGDin the same figure is a surplus gas discharger connected into a portion of pipe 105.

The present invention relates, specifically, to improvements over the gas containing bag 104 contemplated by the invention of said Japanese Patent No. 206,051, cited above, to be made of such a soft, resilient, gas-tight, durable and flexible material as is mentioned above, and concerns, more particularly, a gas-containing cell made with metal plates in its major parts and so constructed by hinging the metal plates with joint seaming material such as vinyl resin, synthetic rubber or a similar material, or metal sheet of a flexible structure, so that the metal plates as fabricated together will fold in or out according as the volume of sealing gas varies.

The objects of the present invention are to maintain a constant sealing-gas pressure, usually at atmospheric pres sure, when the gas goes into, or comes out, of the gascontaining cell owing to the transformer temperature change which causestheoil level in the conservator to vary and, consequently, changes the volume of gas con tained in the conservator; especially to effectively prevent ambient air from permeating through the structural materials of the cell into its interior in order to safeguard the insulation oil against deterioration; and, further still, to provide a gas-containing cell capable of being readily constructed and of easily and accurately indicating the volume of gas contained therein which varies in response to expansion or contraction in volume of the transformer insulation oil.

Hereinafter the present invention will be described in detail by reference to the accompanying drawings wherein examples of application of this invention are presented.

In the drawings,

FIG. 1 is a side view, with some parts shown in section, of an oil-immersed transformer provided with a prior type nitrogen-gas cushioning device.

FIGS. 2 through 10, inclusive, illustrate the expansible cell for example to be used on the transformer shown in FIG. 1. Of these figures, FIG. 2 is a developed view of the metal plates used in the construction of the expansible cell; FIG. 3 represents a joint seam construction, in a cross section view, with the metal plates joined in a seam formed with a flexible and gas-tight material; FIG. 4 represents another joint seam formed by connecting a corrugated elastic metal sheet to the metal plates by Welding or with the use of a bonding compound; and F168. 5, 6' and 7 are a front, a side and a plan view, respectively in that order, of the gas containing cell of this invention in a contracted state wherein its internal volume has decreased approximately half the full size.

FIG. 8 is the plan view where the cell has assumed its maximum volume; FIG. 9 is a plan view of the cell in contraction; and FIG. 10 shows the condition of the gas-containing cell of this invention as installed in the outer housing made with metal plates.

FiG. 11 is the plan view where the cell has expanded to present a rectangular form in its plan view.

FIG. 12 represents stacked units in a partial cut-away view, each unit being a combination of a gas-containing cell and a housing.

According to this invention, eighteen metal plates, as shown in FIG. 2, comprising six rectangular plates 1,

Z 6, six triangular plates 7, 8 12 and six triangular plates 7', 8 12 that are respectively identical with plates 7, 8 12, are arranged in the manner illustrated in FIG. 2 in order to construct the cell. Of these metal plates, the six rectangular plates which form the major part of the cell, namely, front plate 1, side plates 2, 3, back plate 4, and side plates 5, 6 are jointed one to another along the adjoining lengthwise edges; and the free edge of plate 6 is jointed with that of plate 1, so that a square tube-like form constituting the siding of the cell will result. It should be noted that the said metal plates 2, 3 or 5, 6 forming one folding side, of the tube, respectively, are equal in length to the said front or back plate 1 or 6, and in width to one half or less than one half of the said front or back plate. Each hinge seam of the metal plates is to be made in the manner shown in FIG. 3 wherein a soft, resilient, gastight and durable vinyl resin, synthetic rubber or any other similar seam material 13 is bonded on the inner and outer sides of the metal, or in the manner shown in FIG. 4 wherein a relatively thing corrugated metal sheet 14 having required flexibility is jointed ,to the edges of metal plates by welding or with the use of a bonding compound. To the top and bottom edges of plate 1 and plate 4 are similarly jointed equally sized equilateral triangular plates 7, 7' and 10, 10 in that order for folding, one triangle to one edge, as shown in FIG. 2. Again, to the top and bottom of edges of folding plates 2, 3, 5, 6 are jointed in a simlar manner folding equally sized triangular plates 8, 8, 9, 9', 11, 11', 12, 12'. The edges that are free at this stage are similarly jointed edge to edge so that an enclosure or cell, shown in FIGS. 5, 6, 7 will result, withthe triangular folding plates 7, 8, 9, 10, 11, 12 forming a ceiling of the cell while the folding plates 7', 8, 9', 10', 11', 12 form its bottom. It should be noted, however, that along triangular gaps, shown in the developed view of FIG. 2 as 15, 16, 16', are provided in the joints at the top as well as bottom edges of side plates 2, 3, 5, 6 for the purpose of facilitating the folding-in movement of the cell ceiling and bottom when the cell contracts in operation causing its structure to fold in. A gas communicating fitting 17, to be connected with pipe 105 leading into the conservator 107 of FIG. 1, is provided at the center, in the lower part or in any other desired part of the front plate 1.

It will be readily understood from the construction, thus far described, of the expansible cell of this invention that the cell is capable of folding in or out according as the volume of contained gas increases or decreases.

FIGS. 5, 6 and 7 are a front, a side and a plan view, respectively in that order, of the cell whose contents have decreased to approximately one half, in volume, of what it will contain when fully expanded. FIG. 8 is a plan view of the cell containing the maximum volume of gas and FIG. 9 is another plan view illustrating the cell in its further folded state with the gas almost evacuated out.

It should be noted also that, if the cell is constructed to have a rectangular cross section, unlike the case de picted in FIG. 8 where the cross section is square in shape, the triangular plates 7, 7, 10, 10 are replaced by trapezoid-shaped plates in the manner shown in FIG. 11.

FIG. 10 is a side view illustrating the expansible cell, with the contained gas partially evacuated, of this invention installed within a housing 18 corresponding to the housing 106 in FIG. 1 and also a method of mounting the said cell in the housing. In this arrangement, the front plate 1 is rigidly attached to an inner side of the housing 18 by means of appropriate fastening bolts 19, and a plate 20; and wheels 21 are provided on the top portion of the back plate 4, and also on the bottom portion, if desired, so that, by means of the Wheel, back plate 4 of the cell will slide sidewise on, and move as guided by, the rails 22, which rails are fixed to the top of the housing and also to the bottom of said housing, if desired. A side wall of' the housing 18 is provided with a long horizontal peeping window P, whose edge may he graduated if desired, in order that the displacement of back plate 4 in proportion to an expansion or contraction of the cell can be visually observed.

FIG. 12 illustrates a case wherein the cell and housing are combined into a unit construction and a number of these units, commensurate to the capacity of the transformer being served, are stacked and installed to sufficiently take care of gas-volume change under practically constant pressure. In such a case as this, each cell of the aforementioned construction is positioned horizontally, with front plate 1 coming on the bottom side and attached rigidly to the housing by means of flat bars 23, 23, each end of which is fastened to the frame 24 of the housing. The back plate 4, on the top side, is held in free floating condition, and each gas communicating pipe 25 is arranged to lead out from the cell bottom and to extend sidewise into a common pipe connected with the pipe 105 shown in FIG. 1.

Since, according to this invention, the major parts of the expansible cell are made with metal plates so jointed to one another by integrally bonding or connecting the flexible material to the edges of the metal plates as to present flexible folding seams, the contained gas is effectively isolated from ambient air and the amount, of air permeating into the cell interior is extremely small. Moreover, because of such a construction, the contained capacity of the cell is capable of freely conforming to the variable gas volume therein, thus maintaining the gas pressure practically equal to the atmospheric pressure and, furthermore, making it possible to accurately indicate the volume of gas contained in the cell.

What I claim is:

1. An expansible gas-containing cell for use with an oil immersed transformer having an associated gas and oil 4 containing chamber and means for passing the gas between the chamber and the cell as the volume of oil in the transformer varies, comprising a hollow generally rectangular body having opposing parallel front and rear walls, opposing lateral side walls adjoining the front and rear walls, and opposing top and bottom walls adjoining the front, rear and side walls, said front and rear walls being formed by a first two rectangular plates of substantially equal size, each of the side walls being formed by two other rectangular plates each substantially equal in length to the first two plates and equal in width to not more than one half the width of each of the first two plates, each of the top and bottom walls being formed by a first two triangular plates of equal size and by four other triangular plates of equal size and smaller than the first two triangular plates, and a plurality of narrow hinge joints formed of flexible material bonded to and joining flat unfolded edges of each plate to adjacent edges of adjoining plates so that said body forms a leakproof enclosure for gas, and so that the plates in the top, bottom and side walls move angularly to the parallel front and rear walls as the hinge joints flex to expand and contract said body While the gas is passed into and out of said body.

2. A cell unit for use with an oil immersed transformer having an associated gas and oil containing chamber and means for passing the gas between the chamber and the unit as the volume of oil in the transformer varies, comprising a closed housing having a flat vertical side, a hollow expansible generally rectangular gas containing body disposed in said housing, said body having opposing parallel front and rear walls, opposing lateral side walls adjoining the front and rear Walls, and opposing top and bottom walls adjoining the front, rear and side walls, said front and rear walls being formed by a first two rectangular plates of substantially equal size, each of the side Walls being formed by two other rectangular plates each substantially equal in length to the first two plates and equal in width to not more than one half the width of each of the first two plates, each of the top and bottom walls being formed by a first two triangular plates of equal size and by four other triangular plates of equal size and smaller than the first two triangular plates, and a plurality of narrow hinge joints formed of flexible material bonded to and joining flat unfolded edges of each plate to adjacent edges of adjoining plates so that said body forms a leakproof enclosure for gas, and so that the plates in the top, bottom and side walls move angularly to the parallel frontand rear walls as the hinge joints flex to expand and contract said body while the gas is passed into and out of said body, one of the first two plates being secured to said side of the housing, said one plate and said side having registering openings providing a passage for gas between said body and said chamber.

3. A cell unit according to claim 2, further comprising wheel means supporting the other of the first two plates so that said body expands and contracts freely while rolling on said wheel means and the other of the first two plates remains parallel to said one plate.

4. A cell unit according to claim 3, wherein said housing has another side provided with an observation window so that expansion and contraction of said body is visible through said window.

5. A cell assembly for use with an oil immersed transformer having an associated gas and oil-containing chamber and means for passing the gas between the chamber and said assembly as the volume of oil in the transformer varies, comprising a closed housing having a plurality of flat vertical parallel sides, a plurality of hollow expansible generally rectangular gas-containing bodies disposed in said housing, each of said bodies having opposing parallel front and rear walls, opposing lateral side Walls adjoin-v ing the front and rear walls, and opposing top and bottom walls adjoining the front, rear and side walls, said front and rear Walls being formed by a first two rectangular plates of substantially equal size. each of the side walls being formed by two other rectangular plates each substantially equal in length to the first two plates and equal in width to not more than one half the width of each of the first two plates, each of the top and bottom walls being formed by a first two triangular plates of equal size and by four other triangular plates of equal size and smaller than the first two triangular plates, and a plurality of narrow hinge joints formed of flexible material bonded to and joining flat unfolded edges of each plate to adjacent edges of adjoining plates so that said body forms a leakproof enclosure for gas, and so that the plates in the top, bottom and side walls move angularly to the parallel front and rear walls as the hinge joints flex to expand and contract said body while the gas is passed into and out of said body, one of the first two plates of each body each being secured to a different one of the sides of said housing and having an opening therein, and conduit means connected in common to the opening in each of said one of the first two plates for passing gas between the bodies and said chamber.

6. An expansible gas-containing cell for use with an oil immersed transformer having an associated gas and oil containing chamber and means for passing the gas between the chamber and the cell as the volume of oil in the transformer varies, comprising a hollow body having a substantially rectangular cross-sectional shape when fully expanded, said body being formed by a plurality of substantially rectangular plates, a plurality of triangular plates, and narrow hinge joints formed of flexible material integrally bonded to flat unfolded edges of adjoining plates so that the body forms a leakproof enclosure for gas, and so that the joined plates move angularly to each other as the hinge joints flex to expand and contract said body while the gas is passed into and out of said body.

7. A cell unit for use with an oil immersed transformer having an associated gas and oil containing chamber and means for passing the gas between the chamber and the unit as the volume of oil in the transformer varies, comprising a closed housing having a flat vertical side, a hollow expansible generally rectangular gas-containing body disposed in said housing, said body being formed by a plurality of substantially rectangular plates, a plurality of triangular plates, and narrow hinge joints formed of flexible material integrally bonded to flat unfolded edges of adjoining plates so that the body forms a leakproof enclosure for gas, and so that the joined plates move angularly to each other as the hinge joints flex to expand and contract said body while the gas is passed into and out of said body, one of said rectangular plates being secured to said side of the housing, said one side of the housing and said one plate having registering openings providing a passage for gas between said body and said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 

